[sanitizer] Move the errno/ENOMEM allocator checks logic to separate .cc

Summary:
The fact that `sanitizer_allocator_checks.h` is including `sanitizer_errno.h`
creates complications for future changes, where it would conflict with `errno.h`
definitions on Android and Fuchsia (macro redefinition).

By moving the portion that sets errno in the checks to a separate compilation
unit, we avoid the inclusion of the header there, which solves the issue.

Not that it is not vital to have that function in a header as it is called as a
result of an unlikely event, and doesn't need to be inlined.

Reviewers: alekseyshl

Reviewed By: alekseyshl

Subscribers: kubamracek, llvm-commits, mgorny

Differential Revision: https://reviews.llvm.org/D38706

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@315319 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 7 insertions, 2 deletions

diff --git a/lib/sanitizer_common/sanitizer_allocator_checks.h b/lib/sanitizer_common/sanitizer_allocator_checks.h
index b72f541a4..b61a8b2eb 100644
--- a/lib/sanitizer_common/sanitizer_allocator_checks.h
+++ b/lib/sanitizer_common/sanitizer_allocator_checks.h
@@ -15,17 +15,22 @@
 #ifndef SANITIZER_ALLOCATOR_CHECKS_H
 #define SANITIZER_ALLOCATOR_CHECKS_H
 
-#include "sanitizer_errno.h"
 #include "sanitizer_internal_defs.h"
 #include "sanitizer_common.h"
 #include "sanitizer_platform.h"
 
 namespace __sanitizer {
 
+// The following is defined in a separate compilation unit to avoid pulling in
+// sanitizer_errno.h in this header, which leads to conflicts when other system
+// headers include errno.h. This is usually the result of an unlikely event,
+// and as such we do not care as much about having it inlined.
+void SetErrnoToENOMEM();
+
 // A common errno setting logic shared by almost all sanitizer allocator APIs.
 INLINE void *SetErrnoOnNull(void *ptr) {
   if (UNLIKELY(!ptr))
-    errno = errno_ENOMEM;
+    SetErrnoToENOMEM();
   return ptr;
 }